Hi,

is this a know problem? Newest Dovecot 2.3.4 package from repo.dovecot.org , Debian Stretch (fully upgraded).

Nov 29 14:25:11 server00 dovecot: lmtp(16854): Panic: file ostream-dot.c: line 208 (o_stream_dot_sendv): assertion failed: ((size_t)ret == sent + added)

Is this proxying LMTP traffic?

dovecot/lmtp [local DATA](_start+0x2a) [0x565287c310ca]

Based on this I was thinking it wouldn't be. But this apparently happens only with sending SMTP/LMTP traffic with SSL. So do you think it's SSL-related with you also? https://www.dovecot.org/pipermail/dovecot/2018-November/113532.html